Welcome to Hybrid Compute

How to build with Hybrid Compute

Welcome to Hybrid Compute

Hybrid Compute is a system for interacting with the outside world from within solidity smart contracts. Ethereum is a computer with multiple strong constraints on its internal architecture and operations, all required for decentralization. As such, things that most developers take for granted - low cost data storage, audio and image processing, advanced math, millisecond response times, random number generation, and the ability to talk to any other computer - can be difficult or even impossible to run on the Ethereum "CPU". Of course, the benefits of decentralization far outweigh those limitations, and therefore, tools are desirable to add missing functionality to the Ethereum ecosystem. Hybrid Compute is one such tool.

Hybrid Compute is a pipe between (1) Boba's Geth (aka sequencer), which takes transactions, advances the state, and forms blocks, and (2) your server. To use this pipe, all you need is a smart contract on Boba that makes Hybrid Compute calls and an external server that accepts these calls and returns data in a format that can be understood by the EVM. This is not hard to do and we provide many examples which will allow you to quickly build a working Hybrid Compute system.

A typical Hybrid Compute system for gaming or Web3 social networking<>blockchain interoperability has four parts:

1. A contract that uses Hybrid Compute, such as by calling bytes memory encResponse = myHelper.TuringTxV2(serverURL, encRequest); In some places you may find myHelper.TuringTx(...) which is just the previous version (still working) that doesn't support more complex return values such as arrays.

2. A second contract, the TuringHelper, which serves as your standardized door to Hybrid Compute (formerly "Turing").

3. Some BOBA. Each Hybrid Compute call costs 0.01 BOBA, equivalent to about 1 cent at the moment. This fee covers the cost of writing all input calldata and responses from your servers to Ethereum Mainnet.

4. A server which accepts POST requests from Boba's Geth and returns data to it in the right format.

Hybrid Compute is a general purpose pipe between computers and this pipe does not have a native feature set (e.g. storage, cron jobs, cryptographic operations, gaming engines, blockchain history lookups, ...). Rather, it's up to you to deploy servers or endpoints to perform those functions and then expose the right functionality/data to external callers. For many situations, serverless endpoints such as AWS Lambda or Google Cloud Services allow you to build complex logic in just a few lines of code, so if you have not done that before, it's surprisingly easy and we provide many examples for you to use and copy.

Hybrid Compute is general-purpose pipe between computers and not an Oracle. Decentralized Oracles were invented to solve a very specific problem, which is decentralized trustless approximation of the truth (e.g. temperature in NYC, the price of BTC/USD, ...) for later consumption on-chain (e.g. by a DEX or lending protocol). A pipe between computers such as Hybrid Compute has no direct bearing on questions of data authenticity, timeliness, and trust, but rather, those must be tackled by the smart contract deployer and data provider(s) in whatever way is most suitable to their specific use case, industry, and application. To reiterate, Hybrid Compute is a pipe, not an Oracle.

On chain Oracles typically operate in a push manner, meaning that they update data on a fixed schedule (e.g. every 15 seconds), even when those data are not being used. This push update schedule allows calling smart contracts to have confidence that the data they pull are current, but a fixed push update cycle comes at high gas expense that does not decrease in time of low data utilization.

A system like Hybrid Compute is typically configured in the opposite manner, as a pull system, where nothing happens until a smart contract needs data or compute. In that case, the external API services the Hybrid Compute call just in time during the EVM execution flow. This means that systems that use Hybrid Compute have zero baseline gas consumption and provide compute or data only when needed.

Hybrid Compute is invoked when needed during the normal EVM execution flow, and therefore, transactions are atomic. Notably, computations later in the EVM execution flow can operate on responses from your off-chain servers all in one transaction.

As noted, Hybrid Compute is not an Oracle. However, Hybrid Compute writes all initial calldata and server responses to Ethereum Mainnet, and therefore, external parties can see those inputs and outputs. In theory, this may allow third parties to detect fraud or even challenge Hybrid Compute calls, but such functionality remains to be developed.

Since developers (i.e. you) control all of their keys and Hybrid Compute is just a pipe, there are no special security considerations when using Hybrid Compute. Notably - we do not provide data or compute endpoints for you to query - you have to build, secure, and run those.

Hybrid Compute has two security/control features:

• First, when you set up Hybrid Compute, you register the address of your TuringHelper with the TuringBilling contract. This prevents unauthorized contracts from using your on chain infrastructure.

• Second, the Boba Geth provides the address of the calling contract to your servers and endpoints. This allows you to limit use of your public data- or compute- endpoints to contracts that you have specifically approved.

The first mechanism prevents unauthorized use of your on-chain resources and the second one prevents unauthorized use of off-chain resources.

Here are five fully worked out examples for you to build on:

• Use Hybrid Compute to build a CAPTCHA-gated token faucet

• Use Hybrid Compute to mint NFTs with random attributives

• Do all stableswap quadratic math off-chain, just in time

• Query centralized off-chain price feeds

• Connect on-chain events with commercial KYC providers

There is more information on setting up your own servers and compute endpoints here:

• Hybrid Compute API Endpoints

Separately, there is a new system to help you deploy all the right contracts and set up a working test system at [Mainnet: turing.boba.network].

Have fun using hybrid_compute and contact us right away if you run into any problems!

Telegram for Developers Project Telegram Discord

There is a community-built factory contract for Hybrid Compute helper. You can deploy, manage, and fund your Hybrid Compute helpers all through a graphical interface.

• github: https://github.com/medieval-dao/turing-subscription